Improvement in furnace-doors



'1. W. RODGERS.

FURNACE DOOR.

No. 191,474. Patented May 29,1877.

12g! Ag. 2.

I W v W8 N.PEI'ERS, PHOTDLITHOGIAFHER. WASHINGTON- D C UNITED STATESPATENT OFFICE.

THOMAS W. RODGERS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO EDWARD H.ASHCROFT, OF SAME PLACE.

IMPROVEMENT IN FURNACE-DOORS.

Specification forming part of Letters Patent No. 191,474, dated May 29,1877; application filed April 27,1877.

To all whom it may concern.-

Be itknown that I, THOMAS W. RODGERS, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Furnace-Doors; and I do hereby declare that thefollowing is a full, clear, and exact description thereof, which willenable others skilled in the art to which it appertains to make and usethe same, reference being bad to the accompanying I drawings, and toletters of reference marked thereon, which form a part of thisspecification.

Figure 1 is a front elevation of my improved door, showing the frame inwhich it is placed, the outer curved plate of the door, the shaft uponwhich it .turns, and the counterbalances and Fig. 2 is a transversesection on line as a of Fig. 1, showing the parts above referred to andthe interior plate of the door.

Corresponding letters denote like parts in both figures.

This invention relates to that class of furnace-doors which are providedwith counterbalance weights for the purpose of retaining the doors inmore or less open, or in their closed, positions and it consists inproviding such doors with an inwardly-curved plate for closing theaperture in the frame through which the fuel is inserted, the objectbeing to cause the air which enters the furnace through the aperture inthe frame or arch-front when the door is partially open to impingedirectly upon the burning fuel.

It has been customary heretofore to construct counterbalanced doors withthe plate curved outwardly at its center; but this has been found not tobe the best method of construction, for the reason that the air enteringunder the lower edge of the door comes directly in contact with thecurrent of air passing through the grates and the gases arising from thefuel thereon, and is thus carried directly toward the rear of thefurnace without being allowed to impinge directly upon the fuel, while adoor, having its central portion curved inward, as in my case, gives adirectly .downward direction to the air as it passes its lower edge, andthus causes it to impinge immediately upon the fuel with a force due toits velocity.

In constructing furnaces with my improved door attached, I form anaperture, A, in the wall of a furnace, or in a frame, A, to be attachedthereto. To the furnace or to the plate a frame-work, B B, is attached,in the upper surfaces of which are formed bearings for the reception ofa shaft soon to be described. The eud walls of this frame are of theform shown in Fig. 2, for the purpose of preventing the ingress of airat the ends of the door when it is closed, or above it when it ispartially opened, the plate B preventing the ingress of air above thedoor at all times. Into bearings U 0, formed in the upper surface of theframe B B, there is placed a shaft, D, or, it may be, journals formedupon the ends of the door. To that portion of the shaft D which isbetween the walls B B the door is secured, its lengthbeing such as tocause it to extend from one wall to the other, and yet not prevent itfrom turning between them. The plate E, which is the'door proper, may becomposed of cast or of wrought metal, it being secured to the shaft inany suitable manner; or, when made of cast-iron, it may have journalsformed upon its ends, which are to be of sufficient length to cause themto pass through the journals of the frame, and receive upon their outerends counter-balancing weights F F, so that, in whatever position thedoor may be placed, Whether full open for the insertion of fuel, closedentirely, or partially open for the admission of air, it will be soheld, which result will be accomplished even when the door is placedupon seagoing vessels, the boilers of which have their positions changedby the waves of the Water or by the rolling of the vessel.

The feature of novelty in my improvement over doors such as have beenhereinbefore described is, that the plate which constitutes the doorproper, and which is shown at G, Figs. 1 and 2, is curved inward at itscenter, whereby the air which is caused to pass its lower edge whenpartially open is made to impinge directly upon the burning fuel, and sois caused to mingle more fully with the gases arising therefrom than itis when the door is curved outwardly at the same point. This door may beprovided with perforations, as shown in Fig. 1, and may have adeflectingplate placed in the rear thereof, as shown at H, Fig. 2, or itmay be without the perforations, and the deflecting-plate may bedispensed with.

Having thus described myinvention, what I claim, and desire to secure byLetters Patent, 1s-

A counterbalanced furnace-door, the swinging plate of which is curvedinward in the direction of its greatest length, substantially as and forthe purpose set forth.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two witnesses.

THOMAS WILLIAM RODGERS.

Witnesses:

F. T. TAPLEY, MARTIN LUscoMB.

